Precise End‐Group Conjugated‐Site Isomerization of Wing‐Typed Dimeric Acceptors Enables 20.32% Efficiency Organic Solar Cells
Abstract
ABSTRACT Molecular isomerization has been proven as an effective strategy to optimize the backbone geometry of photovoltaic materials and improve power‐conversion‐efficiency (PCE) of organic solar cells (OSCs). However, the precise isomerization of dimeric acceptors and their effect on optoelectronic and photovoltaic properties have been rarely studied. Herein, four isomeric wing‐typed dimeric acceptors (named Dimer‐1, Dimer‐2, Dimer‐3, and Dimer‐4) with an alkylated linker are developed to investigate how different conjugated‐sites of end‐groups (methoxy‐substituted EG1 and methoxy‐free EG2) manipulate molecular packing and optoelectronic properties. Among them, Dimer‐2, with two inside EG1 and two outside EG2 groups, show superior molecular packing, crystallinity, and photoluminescence. Therefore, the PM6:Dimer‐2‐based OSC achieves a higher PCE of 15.12% with obviously boosted photovoltage and fill factor, mainly due to its optimized morphology and reduced energy loss. Building on this success, Dimer‐2 is introduced into the classic PM6:BTP‐eC9 and D18:L8‐BO pairs to prepare ternary systems with complementary absorption and favorable vertical phase distribution, leading to impressive PCEs of 20.06% and 20.32%, respectively. Notably, 20.32% efficiency is the highest value among ternary OSCs with non‐fully conjugated dimeric acceptors. This work indicates that the precise isomerization of end‐group conjugated‐sites is a feasible approach to developing high‐performance dimeric acceptors and constructing efficient OSCs.
Article Details
Authors (21)
Long Jiang
Jia'nan Hu
State Key Laboratory For Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an China
Kai Xiang
Pengbo Yang
State Key Laboratory For Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an China
Wenyan Su
Kun Wang
Beijing National Laboratory for Molecular Science, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering
Jingwei Xue
State Key Laboratory of Oil and Gas Equipment CNPC Tubular Goods Research Institute Xi'an China
Tengfei Li
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
Yirong Li
Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Shanghai Key Laboratory of Functional Materials Chemistry, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering
Dandan Zhang
Hairui Bai
Rui Sun
Hongxiang Li
College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering
Ruijie Ma
Zefan Yao
College of Chemistry and Molecular Engineering Peking University Beijing China
Qiang Tao
Synergetic Extreme Condition High-Pressure Science Center, State Key Laboratory of High Pressure and Superhard Materials, College of Physics
Guanghao Lu
Frontier Institute of Science and Technology
Yuhang Liu
School of Materials Science and Engineering
Jianhua Chen
Department of Chemical Science and Technology, Yunnan University
Wei Ma
Qunping Fan